正交 IL-2 与 IL-2Rβ 系统驱动 CAR-T 细胞的持久性与活化并清除大肿块淋巴瘤

Chimeric antigen receptor (CAR) T cells induce durable responses in patients with refractory hematological tumors.

However, low CAR T cell activity, poor engraftment, or short in-patient persistence can lead to tumor progression or relapse.

Furthermore, excessive CAR T cell expansion and activation can result in life-threatening cytokine release syndrome (CRS).

Thus, in-patient control of the CAR T cell population is essential. Interleukin-2 (IL-2) is a critical cytokine for T cell proliferation and effector function, but its clinical use is limited by immune-mediated toxicity.

Here, we report on an orthogonal IL-2 receptor and ligand system that enables specific in vivo control of CAR T cell expansion and activation, wherein an orthogonal human IL-2 (STK-009) selectively pairs with an orthogonal human IL-2R (hoRb) expressed on CAR T cells. STK-009 expands hoRb-expressing CAR T cells in the presence and absence of tumor antigen and maintains the presence of stem cell memory T cells (T SCM ) and effector T cells. In preclinical models of human CAR-refractory lymphoma, STK-009 treatment resulted in systemic and intratumoral expansion and activation of hoRb-expressing anti CD19-CD28 CAR T cells (SYNCAR).

The orthogonal IL-2 receptor/ligand system delivers complete responses in large subcutaneous lymphomas, even with substantially reduced CAR T cell doses, by selectively expanding and activating CAR T cells in vivo. STK-009 withdrawal allowed normal CAR T cell contraction, thereby limiting CRS induced by tumor antigen specific T cell activation. These data suggest that the orthogonal IL-2 receptor/ligand system provides the in vivo control necessary to maximize efficacy of CAR T therapies.